Sliver feeding means for high pile fabric knitting machines

ABSTRACT

Device for feeding a plurality of separate slivers to the needles of a high pile fabric knitting machine. The device includes the usual wire-covered doffer and main cylinder and is provided with two or more separate assemblies of feed rolls for delivering sliver to the main cylinder. The separate assemblies of sliver feed rolls are spaced arcuately about the main cylinder, and each assembly is movable radially toward and away from the periphery of the main cylinder. Means are provided to advance each assembly of feed rolls to sliver feeding position, adjacent the main cylinder, when it is to deliver sliver thereto, and to retract the assembly, when its delivery of sliver is to cease. The device also includes means to activate automatically the feed rolls, to deliver sliver, when they reach sliver feeding position, and to deactivate them when they are withdrawn from sliver feeding position. An automatic control system is provided to feed sliver selectively, according to a selected predetermined pattern.

United States Patent [191 There [4 1 Nov. 11, 1975 SLIVER FEEDING MEANS FOR HIGH PILE FABRIC KNITTING MACHINES [75] Inventor: Thomas J. Thore, Tarboro, N.C.

[73] Assignee: Glenoit Mills, Inc., New York, NY.

[22] Filed: Nov. 14, 1973 [21] Appl. No.: 415,744

[52] US. Cl 66/9 B [51] Int. Cl. D04B 9/14 [58] Field of Search 19/98, 105; 66/9 B [56] References Cited UNITED STATES PATENTS 3,122,904 3/l964 Brandt 66/9 B 3,495,422 2/1970 Miller 66/9 B Primary E.\'aminer-Dorsey Newton Attorney, Agent, or FirmMiller, Frailey & Prestia [57 ABSTRACT Device for feeding a plurality of separate slivers to the needles of a high pile fabric knitting machine. The device includes the usual wire-covered doffer and main cylinder and is provided with two or more separate assemblies of feed rolls for delivering sliver to the main cylinder. The separate assemblies of sliver feed rolls are spaced arcuately about the main cylinder, and each assembly is movable radially toward and away from the periphery of the main cylinder. Means are provided to advance each assembly of feed rolls to sliver feeding position, adjacent the main cylinder, when it is to deliver sliver thereto, and to retract the assembly, when its delivery of sliver is to cease. The device also includes means to activate automatically the feed rolls, to deliver sliver, when they reach sliver feeding position, and to deactivate them when they are withdrawn from sliver feeding position. An automatic control system is provided to feed sliver selectively, according to a selected predetermined pattern.

8 Claims, 9 Drawing Figures U.S. Patent Nov. 11, 1975 Sheet10f6 3,918,273

US. Patent Nov. 11, 1975 Sheet 3 of6 3,918,273

US. Patent Nov.11, 1975 Sheet4of6 3,918,273

US. Patent Nov. 11, 1975 Sheet5of6 3,918,273

l l l l M IA N I F O L D US. Patent 'N0v.11,1975 Sheet6of 6 3,918,273

F I g I 8 llJllHllllllllllll SLIVER FEEDING MEANS FOR HIGH PILE FABRIC KNITTING MACHINES SUMMARY OF THE INVENTION The primary object of this invention is to provide a new and improved sliver feeding device for multi-feed high pile fabric circular knitting machines having two or more separate assemblies of sliver feed rolls, for delivering selectively a plurality of different slivers to the main cylinder of the device, according to a predetermined pattern.

A further object of the invention is to provide such a sliver feeding device wherein each assembly of sliver feed rolls is disposed radially of the main cylinder, and is advanceable to the main cylinder to feed sliver thereto, and retractable therefrom when not feeding sliver.

A further object is to provide such a sliver feeding means including a drive mechanism for the sliver feed rolls, whereby the rolls are activated automatically when advanced to sliver feeding position, and deactivated automatically when retracted therefrom.

A further object is to provide a new and improved sliver feeding means to enable a multi-feed high pile fabric circular knitting machine to produce a greater range of fabrics of multi-colored and/or patterned designs.

To achieve the foregoing objective, the invention, in its preferred form, comprises the usual wire-covered doffer and main cylinder, a plurality of separate assemblies of sliver feed rolls for delivering sliver selectively to the main cylinder, a slidable support for each assembly of feed rolls, operative to advance the feed rolls to sliver feeding position and to retract them therefrom when not feeding sliver, means automatically operative to rotate the feed rolls when in sliver feeding position and to cease their rotation when retracted therefrom, and control means for advancing and retracting the separate assemblies of sliver feed rolls selectively.

DESCRIPTION OF THE VIEWS OF THE DRAWING dicated by the arrows 44 of FIG. 1.

FIG. 5 is an enlarged, fragmentary view in section indicated by the arrows 5-5 of FIG. 4.

FIG. 6 is an enlarged, fragmentary view in section indicated by the arrows 6--6 of FIG. 4.

FIG. 7 is a schematic view of an electro-pneumatic control system for the sliver feeding device.

FIGS. 8 and 9 show a modified control system,-

DETAILED DESCRIPTION OF THE INVENTION In FIG. 1 there is shown the knitting head of a high pile fabric knitting machine 12 provided with eight sliver and yarn feeding stations spaced uniformly about the circle of needles 20. Proceeding in the direction of needle rotation, the eight sliver and yarn feeding stations have been designated by the reference numerals 1 to 8 inclusive. Each feeding station includes the usual yarn feeding means (not shown) together with a sliver feeding means or device 19 of this invention.

FIG. 2 shows a sliver feeding device 19, a needle 20, needle cylinder 21, sinker cap 22, sinker ring 23, a sinker 24 and ring gear 25. The latter rotates with the needle cylinder and meshes with the pinion 26, to impart, through conventional and well known drive mechanism, rotative movement to the usual wire-covered doffer 28 and wire-covered main cylinder 30. The device 19 is supported on the head ring 34 of the machine. Base yarn Y is fed to the needles 20 via the usual yarn feed tube T.

In the preferred embodiment shown, the sliver feeding device incorporates (FIG. 4) three separate pairs or assemblies of wire-covered sliver feed rolls 38 and 39, 40 and 41, 42 and 43, for feeding, respectively, slivers 45, 46, 47 to the main cylinder 30. The three assemblies of sliver feed rolls draw their sliver 45, 46, 47 from sources (not shown) via chutes 49, 50, 51, respectively.

Each pair of feed rolls is caused to rotate by ring gear 25 through a drive assembly like that illustrated and described in my co-pending US. patent application Ser. No. 304,099, filed Nov. 6, 1972, entitled Sliver Feeding Means For High Pile Fabric Knitting Machines. More particularly, the drive means for the feed rolls includes pinion 26, the usual shafting and gearing indicated generally by the reference numeral 58, worm 60, gear 62, shaft 64, gear cone 72 (FIG. 4), shaft 74 and a gear selector indicated generally by the reference numeral 90. As explained in my aforesaid application Ser. No. 304,099, gear 84 of the gear selector 90 is slidable axially of shaft 74 so as to permit the selective engagement of gear 88 with one of the gears of the gear cone 72, to vary selectively the speed of rotation of the sliver feed rolls.

The pairs of feed rolls 38 and 39, 40 and 41, 42 and 43, are joumalled for rotation, respectively, in slidable supports I60, 161, 162 spaced arcuately about the periphery of main cylinder 30. Each of the supports 160, 161, 162 is disposed substantially radially of the main cylinder, and is selectively movable toward and away from the peripheral covering of the main cylinder. The supports are slidably mounted in the stationary frame 68 of the sliver feeding device 19.

FIG. 5 illustrates the manner in which feed rolls 38 and 39 are mounted for rotation in support 160, and how the latter is supported slidably in frame 68. Support 160 includes two spaced, elongated, vertical sections 150, 151 mounted slidably within elongated grooves 152, 153 respectively, of frame 68. Sliver feed roll 39 is affixed to transverse rotatable shaft 132 journalled for rotation in-bearings 165 fixed in spaced sections 150, 151 of support 160. The outer portions of the bearings 165 extend freely through elongated slots 155, 156, in frame 68.

Affixed to one end of shaft 132 is a rotatable clutch element 128 of a conventional magnetic clutch 118, which is secured to slide 160 by a bracket I26. Clutch element 128 is provided with a clutch-plate 130. The clutch 118 also includes a second clutch element I20 mounted for rotation on a fixed hollow tube I22 @8- cured to support 68, and disposed externally aBQIII shaft 132. Clutch element includes an axially IIQ able, normally retracted, plate 124. When the cilIIch l 18 is energized, rotatable clutch plate 124 is attrafiiti to and engaged magnetically with clutch plate 130 of clutch element 128.

A sprocket wheel 112 is mounted on one end of shaft 74 (FIGS. 2, 4) and by means of a sprocket chain 114, drives sprocket wheel 116 affixed to the rotatable clutch element 120. Clutch element 120 and its slidable plate 124 are rotated at selected speeds, as determined by the gear cone 72, in the manner explained in my copending application Ser. No. 304,099.

When clutch 118 is energized, and slidable plate 124 attracted to and engaged magnetically with plate 130, the rotational drive of clutch element 120 is imparted to clutch element 128, to drive shaft 132 and sliver feed roll 39 affixed thereto.

Affixed to the opposite end of shaft 32 is a gear 134 which meshes with a gear 136 affixed to a second transverse rotatable shaft 138. The shaft 138 is supported for rotation in slidable support 160 by means of fixed bearings 167, and has affixed thereto sliver feed roll 38. By means of gears 134, 136, the rotational drive of shaft 132 is imparted to shaft 138, to rotate sliver feed rolls 39, 38 in unison.

The outer portions of the bearings 167 extend freely through elongated slots 157, 158 in frame 68. Since clutch 118 is secured to support 160 by bracket 126, and because bearings 165, 167 extend freely through the slots 155, 156, 157, 158, the entire ensemble consisting of rolls 38, 39, their shafts, gearing, etc., together with their clutch 118, advances and retracts with support 160 when it is moved toward or away from the main cylinder 30.

The slidable support 160 is advanced to sliver feeding position by a valve-controlled pneumatic cylinder 171. Referring specifically to FIGS, and 6, a transverse bar 170 affixed to frame 68 supports cylinder 171 with its piston 172. The elongated rod 174 of piston 172 extends outwardly of the cylinder and passes through an aperture in bar 170. Its distal end is affixed to a transverse angle 175 secured to the top edges of sections 150, 151 of support 160. A coil spring 177 is disposed about the external portion of rod 174 and serves to retract piston 172, angle 175 and support 160 and its feed roll ensemble away from main cylinder 30. Cylinder 171 is connected by conduit 178 to a source of compressed air (not shown). When air is permitted to flow through conduit 178 into cylinder 171, piston 172 advances against the force of spring 177, to advance support 160 and its feed rolls 38, 39 to sliver feeding position adjacent main cylinder 30.

A threaded bolt 180, or similar adjustable element, mounted on support 160, limits the extent to which the support and its feed rolls 38, 39 may be advanced toward main cylinder 30 to feed sliver thereto. Likewise, a threaded bolt 181, or similar adjustable element mounted in fixed bar 170 and extending freely through an aperture in angle 175, limits the extent to which spring 177 retracts support 160 and its feed rolls from sliver feeding position, when compressed air is not passing to cylinder 171.

The construction and operation of feed rolls 40, 41 and their support 161, and of feed rolls 42, 43 and their support 162, and their respective ensembles of parts, is exactly like that shown and described in respect of feed rolls 38, 39 and their support 160. Supports 161, 162 include, respectively, pneumatic cylinders 184, 185, springs 187, 188, and stops 190, 191 (FIG. 3). Whenever one of the assemblies of feed rolls is to feed its sliver to the main cylinder, its slidable support is advanced to sliver feeding position, as indicated by the location of rolls 38, 39 in FIG. 4. By control means presently to be explained, the separate assemblies of sliver feed rolls are advanced and retracted selectively to the main cylinder, to feed their sliver thereto accord ing to any predetermined pattern.

As shown in FIG. 2, feed roll 41 mounted in support 161 is provided with a magnetic clutch 193, and feed roll 43 mounted in support 162 is provided with a magnetic clutch 194. The shafts on which the rolls 40, 41 and 42, 43 are mounted are connected by intermeshing gearing (FIG. 3) like gears 134, 136 for shafts 132, 138. A second sprocket wheel (FIG. 5) is affixed to the rotatable element 120 of clutch 118, and by means of sprocket chain 141 drives a sprocket wheel affixed to clutch 193, to impart rotation thereto. By means of a similar sprocket wheel and chain construction 144, clutch 194 is driven from clutch 193. The construction and operation of clutches 193 and 194 is the same as that of clutch 118, whereby the pairs of feed rolls 40, 41 and 42, 43 are rotated selectively when their respective clutches are energized, to deliver sliver to the main cylinder.

A micro-switch 200 is affixed to frame 68 adjacent to support 160. A finger 201 is affixed to support 160, and is adapted to strike a contact arm of switch 200, and thereby close the switch, as support is advanced to sliver feeding position by pneumatic cylinder 171. The closing of switch 200 completes an electric circuit to clutch 118, to energize the clutch and impart rotation to feed rolls 38, 39 to feed sliver 45 to the main cylinder 30. Finger 201 is positioned selectively on support 160 to close switch 200, and start rotation of the feed rolls 38, 39, when support 160 has advanced fully to sliver feeding position. When support 160 is retracted, finger 201 disengages from switch 200 to open the switch. This interrupts the flow of electric current to clutch 118, to stop the rotation of the sliver feed rolls.

A micro-switch 203 and finger 204 are provided for support 161, and a micro-switch 206 and finger 207 for support 162. By means of micro-switch 203 and finger 204, clutch 193 is energized to impart rotary motion to feed rolls 40, 41, to feed sliver 46 to the main cylinder 30, when support 161 has been advanced to sliver feeding position. Similarly, by means of switch 206 and finger 207, clutch 194 is energized to impart rotation to feed rolls 42, 43, to feed sliver 47 to the main cylinder, when support 162 has been advanced to sliver feeding position.

By reason of the foregoing construction, the assemblies of sliver feed rolls are advanced and retracted selectively to and from sliver feeding position. Each pair of feed rolls is activated to deliver sliver to the main cylinder, when in sliver feeding position, and deactivated when retracted therefrom.

1n the preferred operation of this invention, only one of the three separate assemblies of sliver feed rolls are advanced to sliver feeding position at a time, the remaining two assemblies of feed rolls being retained in their retracted, non-feeding position (see FIG. 4). However, if desired, it is entirely possible for the sliver feeding device 19 to be operated so that any two assemblies of feed rolls, or all three assemblies, may advance and feed their slivers simultaneously to the main cylinder 30.

FIG. 7 illustrates one type of electro-pneumatic control system for the sliver feeding. device 19. FIG. 7 shows support 160 and its feed rolls 38l,'39 advanced to sliverfeeding position, with switch 200 closed to energize clutch 118 to impart sliver feeding rotation to the feed rolls. Supports 161 and 162 are retracted from sliver feeding position, with their switches 203, 206 open, and their feed rolls 40, 41 and 42, 43 inactive. As shown, the switches 200, 203, 206 are connected in parallel to an electric circuit indicated generally by the reference numeral 209.

Conduit 178 connects pneumatic cylinder 171 of support 160 to a solenoid valve 211 which, in turn, is connected by conduit 212 to a manifold 213. A conduit 214 connects the manifold to a source of compressed air (not shown). The solenoid valve is electrically connected to a normally open micro-switch 215 mounted on the stationary sinker cap 22 (FIG. 2). When switch 215 is closed, an electric circuit is completed to valve 211, to open the valve and permit compressed air to flow through conduit 178 to cylinder 171, .to advance support 160 to sliver feeding position. An elongated, arcuate cam 216 is secured to the underside of the, rotatable sinker ring 23 (FIG. 2). Each time cam 216 rotates past switch 215, it strikes the contact arm of the latter, to close the switch. As soon as cam 216 has com pleted its travel past switch 215, the'switch is opened automatically, interrupting the flow of electric current to valve 21 1. Thereupon, the valve shuts automatically, and compressed air ceases to flow to cylinder 171. As a result, slide 160 is retracted under the influence of spring 177, whereupon delivery of sliver 45 to the main cylinder ceases.

Thus, upon each revolution of the needle cylinder 21, sliver 45 is fed by rolls 38, 39 to main cylinder 30 for a predetermined period of time, depending on the arcuate length of cam 216.

Pneumatic cylinder 184 of support 161 is connected by conduit 219 to a solenoid valve 220 which, in turn, is connected by conduit 221 to manifold 213. Valve 220 is connected electrically to micro-switch 222, the latter being activated by cam 216 in the same manner as switch 215 is activated, as previously described. Thus, when cam 216 closes switch 222, valve 220 is opened to permit compressed air to flow to cylinder 184, to advance support 161 to sliver feeding position.

Similarly, pneumatic cylinder 185 of support 162 is connected by conduit 224 to solenoid valve 225 which, in turn, is connected by conduit 226 to manifold 213. Valve 225 is connected electrically to micro-switch 227 which, in the manner previously described, is closed periodically by cam 216 to cause support 162 to 'advance to sliver feeding position.

In the arrangement shown in FIG. 7, the microswitches 215, 222 and 227 are spaced uniformly about the needle cylinder 21, i.e., at 120 intervals, and arcuate cam 216 extends along one-third of the circumference of the sinker ring 23. Thus, as needle cylinder 21 and sinker ring 23 rotate, one of the three microswitches always will be closed by the cam, so that one of the three slivers 45, 46, 47 will be fed to the main cylinder 30, depending on which switch is closed. As needle cylinder 21 rotates, the switches 215, 222, 227 are closed successively and the slivers 45, 46, 47 are fed in alternation to the knitting machine 12.

The solenoid valves 211, 220, 225, the manifold 213 and various elements of the electric circuitry for the sliver feeding device 19 may be mounted in a suitable control box 230 which, in turn, is supported at any convenient location on the machine 12. Each of the eight sliver feeding devices for the machine 12 is constructed 'and operates in the manner described in respect of device 19. Each may have an electropneumatic control system like that illustration schematically in FIG. 7. In such arrangement, each of the micro-switches 215, 222, 227 are connected electrically to the solenoid valves for each sliver feeding device, and each such device may be provided with a control box and contents like that illustrated in FIG. 7.

In FIGS. 8 and 9 there is shown a modified electropneumatic control system for the sliver feeding device 19. More particularly, there is provided a rotatable drum 234 supported on frame 235 by means of trunnions 236, 237. A racking mechanism indicated generally by the reference numeral 238 is disposed at one end of drum 234, and serves to rack the drum periodically in a counter-clockwise direction, as indicated in FIG. 9. Racking mechanism 238 includes a pneumatic cylinder 240, connected by conduit 241 to a solenoid valve 242. The latter is connected to a source of compressed air (not shown), and is connected electrically to a micro-switch, such as switch 215, mounted adjacent to the sinker ring 23 of the knitting machine 12. Whenever valve 242 is energized, it opens to permit compressed air to flow to pneumatic cylinder 240, to activate its piston to rack drum 234 in a manner well known in this art.

A plurality of micro-switches 244 are disposed on each side of the drum 234. Each micro-switch 244 is connected electrically to the solenoid valve for the pneumatic cylinder of one of the sliver feed roll assemblies. In a knitting machine having eight sliver and yarn feeding stations, with three separate assemblies of sliver feed rolls for each device 19, a total of 24 switches 244 are provided, 12 of which are mounted on each side of drum 234. A plurality of arcuate cams 245 are mounted on the periphery of drum 234, and are adapted to strike the contact arms of the switches 244 to close them, and complete their electric circuits. By this arrangement, as drum 234 is racked, cams 245 engage selectively their respective micro-switches 244, so that the latter complete electric circuits to their respective sliver feed roll assemblies to cause the same to advance to sliver feeding position and deliver sliver to main cylinder 30. By the arrangement shown in FIGS. 89, each separate assembly of sliver feed rolls in the knitting machine is separately and individually controlled, and is operated to feed sliver selectively and intermittently to the main cylinder 30, according to any selected, predetermined pattern, as established by the spacing and size of the individual cams 245.

Although a preferred embodiment of this invention has been shown and described for the purpose of illustration, as required by Title 35 U.S.C. 112, it is to be understood that various changes and modifications may be made therein without the departing from the spirit and utility of this invention, or the scope thereof as set forth in the appended claims.

I claim:

1. A sliver feeding device for a high pile fabric knitting machine having:

a. a main cylinder,

b. plural assemblies of rotatable sliver feed rolls spaced arcuately about the cylinder,

c. drive means for rotating selectively each assembly of feed rolls to deliver sliver to the cylinder,

d. retractable support means for advancing and retracting each assembly of feed rolls to and from sliver feeding position adjacent the cylinder,

e. control means operative to advance and retract the feed roll support means selectively, and

f. actuating means for the feed roll drive means operative to cause each assembly of feed rolls to rotate when in sliver feeding position.

2. The sliver feeding device of claim 1, wherein the control means includes:

a. fluid actuated means for advancing each support means toward the cylinder to dispose its feed rolls in sliver feeding position, and

b. resilient means urging each support means away from the cylinder.

3. The sliver feeding device of claim 1, wherein the retractable support means includes:

a. a slidable support for each assembly of feed rolls disposed substantially radially of the cylinder and b. fluid actuated means for advancing each slidable support toward the cylinder.

4. The sliver feeding device of claim 3, wherein:

a. each assembly of feed rolls include at least one pair of rotatable feed rolls journalled for rotation within a slidable support and b. resilient means urges ech slidable support away from the cylinder.

5. The sliver feeding device of claim 1, wherein the feed roll actuating means is automatically operative to stop rotation of the feed rolls upon retraction of the feed rolls from sliver feeding position.

6. In a sliver high pile fabric knitting machine having a circle of needles, means for feeding a base yarn to the needles and a plurality of sliver feeding devices for feeding sliver fibers to the needles, each said fiber feeding device including a doffer and a main cylinder, sliver feeding means for feeding selectively a plurality of slivers to each main cylinder comprising:

a. plural assemblies of rotatable sliver feed rolls spaced arcuately about each main cylinder. b. a slidable support for each assembly of feed rolls disposed substantially radially of the cylinder, c. pneumatic means for selectively advancing each slidable support radially toward the cylinder to sliver feeding position, d. resilient means urging each slidable support away from sliver feeding position, e. drive means for rotating selectively each assembly of feed rolls to deliver sliver to the cylinder and f. actuating means for the feed roll drive means operative i. to cause each assembly of sliver feed rolls to rotate and deliver sliver to the cylinder when its support is in sliver feeding position and ii. to cause the feed roll assembly to stop rotating when its support is retracted from sliver feeding position.

7. The knitting machine of claim 6, further including control means for each assembly of sliver feed rolls operative to cause the pneumatic means to advance the feed roll supports to sliver feeding position, said control means comprising:

a. an electro-pneumatic system connected to each feed roll assembly,

b. a plurality of micro-switches in each electropneumatic system and c. a plurality of cams operative to actuate the switches and energize each electro-pneumatic system selectivelyv 8. The knitting machine of claim 7 wherein the control means includes:

a. a rotatable drum b. a plurality of cams mounted on the drum, and

c. a plurality of micro-switches disposed adjacent the drum to be actuated by the cams. 

1. A sliver feeding device for a high pile fabric knitting machine having: a. a main cylinder, b. plural assemblies of rotatable sliver feed rolls spaced arcuately about the cylinder, c. drive means for rotating selectively each assembly of feed rolls to deliver sliver to the cylinder, d. retractable support means for advancing and retracting each assembly of feed rolls to and from sliver feeding position adjacent the cylinder, e. control means operative to advance and retract the feed roll support means selectively, and f. actuating means for the feed roll drive means operative to cause each assembly of feed rolls to rotate when in sliver feeding position.
 2. The sliver feeding device of claim 1, wherein the control means includes: a. fluid actuated means for advancing each support means toward the cylinder to dispose its feed rolls in sliver feeding position, and b. resilient means urging each support means away from the cylinder.
 3. The sliver feeding device of claim 1, wherein the retractable support means includes: a. a slidable support for each assembly of feed rolls disposed substantially radially of the cylinder and b. fluid actuated means for advancing each slidable support toward the cylinder.
 4. The sliver feeding device of claim 3, wherein: a. each assembly of feed rolls include at least one pair of rotatable feed rolls journalled for rotation within a slidable support and b. resilient means urges ech slidable support away from the cylinder.
 5. The sliver feeding device of claim 1, wherein the feed roll actuating means is automatically operative to stop rotation of the feed rolls upon retraction of the feed rolls from sliver feeding position.
 6. In a sliver high pile fabric knitting machine having a circle of needles, means for feeding a base yarn to the needles and a plurality of sliver feeding devices for feeding sliver fibers to the needles, each said fiber feeding device including a doffer and a main cylinder, sliver feeding means for feeding selectively a plurality of slivers to each main cylinder comprising: a. plural assemblies of rotatable sliver feed rolls spaced aRcuately about each main cylinder, b. a slidable support for each assembly of feed rolls disposed substantially radially of the cylinder, c. pneumatic means for selectively advancing each slidable support radially toward the cylinder to sliver feeding position, d. resilient means urging each slidable support away from sliver feeding position, e. drive means for rotating selectively each assembly of feed rolls to deliver sliver to the cylinder and f. actuating means for the feed roll drive means operative i. to cause each assembly of sliver feed rolls to rotate and deliver sliver to the cylinder when its support is in sliver feeding position and ii. to cause the feed roll assembly to stop rotating when its support is retracted from sliver feeding position.
 7. The knitting machine of claim 6, further including control means for each assembly of sliver feed rolls operative to cause the pneumatic means to advance the feed roll supports to sliver feeding position, said control means comprising: a. an electro-pneumatic system connected to each feed roll assembly, b. a plurality of micro-switches in each electro-pneumatic system and c. a plurality of cams operative to actuate the switches and energize each electro-pneumatic system selectively.
 8. The knitting machine of claim 7 wherein the control means includes: a. a rotatable drum b. a plurality of cams mounted on the drum, and c. a plurality of micro-switches disposed adjacent the drum to be actuated by the cams. 